The present invention relates to a hydraulic control arrangement for control of fluid flow to and from a consumer device. The arrangement comprises a three-position valve having a valve member movable between a neutral position closing at least one conduit leading to the consumer device and two working positions respectively connecting the consumer device with a source of pressure fluid and to a return flow conduit leading to a reservoir, a reversing valve for connecting the source of pressure fluid directly to the return flow conduit and a control conduit connected with the reversing valve. A throttle is provided in the control conduit which produces a pressure difference which can act on the valve member of the reversing valve to move the latter against the force of a spring, and means for control of the consumer device independent of the load pressure acting thereon.
In a hydraulic control arrangement of the aforementioned kind two control conduits are provided, both of which are controllable from the valve member of a three-position valve. A first one of the control conduits, provided with a throttle, is controlled from the valve members of all three-position valves and serves for control of the reversing valve, whereas the second control conduit serves for return of the load pressure from the consumer devices. Due to the necessity of two control conduits, this known arrangement is extremely expensive to produce and it requires three control connections at each three-position valve. This arrangement has the further disadvantage that during simultaneous operation of two three-position valves the control of the consumer devices connected thereto will be detrimentally influenced. The known control arrangement includes further a check valve in the second control conduit which prevents return flow of pressure fluid from the consumer device to the reversing valve. In this arrangement it may happen that the lowering of the load occurring during such return flow is in practice negligibly small, but that the pressure built up to control the reversing valve, is due to the check valve, only possible from the side of the pump providing the necessary pressure fluid and that this lowering of the load will therefore occur slower than in an arrangement which omits this check valve.